Bottom Paint Question

[joker460]

I purchased a 1999 B352 last year and have had it stored and covered on land over the winter months.

Now I'm trying to figure out what type of bottom paint was used.

Is there a way to determine visually or by touch, the type of bottom paint used? For example the difference between a hard paint and ablative paint.

I touched the hull today and the green color rubbed off onto my hand. Not very scientific I know.

Thanks

 

[Joe]

You can put ablative over hardshell....... but not hardshell over ablative. The fact that you store the boat out of the water indicates that the existing paint is probably ablative. AND.... it is also likely that you will choose an ablative type paint for the future... so... unless you are intending to use a hardshell, modified epoxy paint on your boat, you don't need to remove the existing paint.... no matter what it is... unless, of course, you want to put on a barrier coat.

But, let's say you just want to know... then I would ask the yard manager where you store the boat for his opinion. I would call the previous owner, or check the maintenance records he left with the boat (he did leave maintenace records, didn't he?) I am no expert, but my hardshell paint will flake when I try to scrape it... I don't think ablative paint will behave that way... but I defer to the more experienced contributers here.

 

[joker460]

You can put ablative over hardshell....... but not hardshell over ablative. The fact that you store the boat out of the water indicates that the existing paint is probably ablative. AND.... it is also likely that you will choose an ablative type paint for the future... so... unless you are intending to use a hardshell, modified epoxy paint on your boat, you don't need to remove the existing paint.... no matter what it is... unless, of course, you want to put on a barrier coat.

But, let's say you just want to know... then I would ask the yard manager where you store the boat for his opinion. I would call the previous owner, or check the maintenance records he left with the boat (he did leave maintenace records, didn't he?) I am no expert, but my hardshell paint will flake when I try to scrape it... I don't think ablative paint will behave that way... but I defer to the more experienced contributers here.

Thanks for the reply.
The boat was from Atlanta Georgia and was always in fresh water.
Lifted 4 years ago for the bottom paint. The previous owner is trying his best to find the previous documentation.
I haven't tried scaping but I will. There are areas around the lead keel wing that have worn completely away which leads me to think it's an ablative paint since a hard paint would still be there. The paint in those areas doesn't look chipped but worn.

 

[fstbttms]

You can put ablative over hardshell....... but not hardshell over ablative.

Not necessarily true. Your average modified epoxy can be applied over your average ablative with excellent results.

There are areas around the lead keel wing that have worn completely away which leads me to think it's an ablative paint since a hard paint would still be there. The paint in those areas doesn't look chipped but worn.

What you are attributing to ablation is more likely abrasion. When a keel gets down into the mud or sand, the paint can be abraded off in short order, regardless of whether it's a hard paint or not. I would not assume that you have an ablative based on this.

 

[RON20406]

Joker, since you just bought the boat and are not quite certain what type of bottom paint was previously used, why not clean up the existing paint with a light cosmetic sanding of 80 grit sandpaper and"spot in" the areas that have been degraded with a bottom paint of your choice. Be careful to slightly overlap the new paint into the old paint and feather the edges of the old paint for the overlap so your experiemnt has the best chance of success. If there are adhesion problems in the overlapped areas after you haul the boat in the Fall, you can be fairly certain you have two different types of bottom paint. If, however, the adhesion is good and you don't see any lifting, you probably have the correct paint. Since your season is fairly short in Ontario, like ours in Illinois, you won't be sacrificing much money (one quart of bottom paint) or time for this experiment. Then, the following year, you can agressively sand the bottom and try one coat of the new paint. If there is not flaking in the Fall, you're home free. I would however use a foam roller for the second experiment which should give you a thinner mil than a napped roller so that if the paint is ultimately not compatible you will have an easier sand for the final correction. Good luck and good sailing, Ron

 

[joker460]

Thanks for the replys.

I like Rognvald's suggestion. As you say the season is so short it shouldn't make a big difference.

 

[Joe]

Not necessarily true. Your average modified epoxy can be applied over your average ablative with excellent results.


What you are attributing to ablation is more likely abrasion. When a keel gets down into the mud or sand, the paint can be abraded off in short order, regardless of whether it's a hard paint or not. I would not assume that you have an ablative based on this.

Correction noted..... now.... can you answer Joker's questions?

 

[RON20406]

Syllogistic reasoning

Correction noted..... now.... can you answer Joker's questions?

Simple syllogistic reasoning: If A is incompatible with B because of poor adhesion and B is a known factor (ie; an ablative paint you have chosen for the unpainted spots) then we can safely solve the unknown factor A as being either an epoxy or teflon paint if, in fact, A and B are known to be incompatible. That's simple enough for me without creating a science experiment or a neurotic trip to a chemical lab. Paint your bottom, sail your boat! Good luck and good sailing, Ron

 

[mark_swart]

I've heard you can go by tasting it -- hard paints taste more like jolly ranchers, while ablatives taste sort of like cotton candy.

Just kidding : ) I would have given a serious answer but I believe all of the previous ones were good!